• 제목/요약/키워드: WR

검색결과 280건 처리시간 0.03초

교차도파관 방향성결합기의 방향성 성능 개선 (Directivity compensation of crossed waveguide directional coupler)

  • 김동현;양두영
    • 대한전자공학회논문지TC
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    • 제44권9호
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    • pp.63-69
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    • 2007
  • 교차도파관 방향성결합기는 결합도가 증가함에 따라 방향성이 감소하는 특성을 갖고 있다. 본 논문에서는 교차도파관 방향성결합기의 방향성을 향상시킬 수 있도록 X형 슬롯 쌍의 구조 변수를 수정하고, 그에 따른 관계식을 제안하였다. 그리고 K밴드 주파수 대역에서 그 관계식을 토대로 설계된 교차도파관 방향성결합기는 WR42 도파관을 사용하여 제작하였다. 측정한 결과 WR42 주파수 대역인 $18GHz{\sim}26.5GHz$에서 평균 결합도는 21.05dB, 방향성은 최소 23.9dB로 나타났다.

추출조건을 달리한 마늘 추출물이 Triton WR-1339 유발 고지혈증 흰주의 체내 지질대사에 미치는 영향 (Effect of Various Garlic Extracts on Hyperlipidemia Rats Induced by Triton WR-1339)

  • 정명수;김혜자;조화은;최윤희;한중호;이기남
    • 대한예방한의학회지
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    • 제13권1호
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    • pp.69-80
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    • 2009
  • The purpose of this study was to investigate the effect of garlic(Allium sativum L.) extracts with extraction conditions on hyperlipidemia prevention. The extracts prepared for garlic by hot temperature extraction(HG), low temperature extraction(LG), UMPM extraction(UG), fermentation(FG) and black garlic hot temperature(BG) method. To evaluate of hypolipidemia effect in vivo, we examined serum and liver lipid profiles of Triton WR-1339 induced hyperlipidemia rats. Serum triglyceride and total cholesterol levels in UG group were significantly higher than control group. Liver total cholesterol content in LG group and liver triglyceride in UG group was significantly lower than control group.

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마금탕(麻芩湯)이 흰쥐의 고지혈증 병태에 미치는 영향 (Effects of Mageum-tang on the Hyperlipidemia in Rats)

  • 노승원;김정범
    • 동의생리병리학회지
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    • 제24권2호
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    • pp.319-327
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    • 2010
  • This study was designed to investigate the hyperlipidemia-healing effect of liquid extract from Mageum-tang(麻芩湯), it was performed on the hyperlipidemia of rats induced by high cholesterol diet and Triton WR-1339. We prepared two types of hyperlipidemia model in rats induced by high cholesterol diet and Triton WR-1339. The amount of total cholesterol, HDL-cholesterol, LDL -cholesterol, triglyceride, phospholipid, free fatty acid, the activity of superoxide dismutase(SOD), and glutathione were measured. The liquid extract from Mageum-tang showed significant decreasing effects on total cholesterol, LDL- cholesterol, triglyceride, phospholipid, free fatty acid in the both model. And it showed significant increasing effects on HDL-cholesterol, the activity of SOD in both model and amount of glutathione in Triton WR-1339 model. These results suggest that liquid extract from Mageum-tang has healing efficacy on hyperlipidemia induced by high cholesterol diet and Triton WR-1339.

광 버스트 스위칭 네트워크와 파장 라우팅 네트워크의 성능 비교 (A Performance Evaluation on Optical Burst Switched Networks and Wavelength Routed Networks)

  • 유명식;정연미;홍현하
    • 한국통신학회논문지
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    • 제28권5B호
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    • pp.404-413
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    • 2003
  • 광 네트워크의 형태가 IP over WDM의 형태로 발전해 나아감에 따라 이러한 광 도메인 내에서의 스위칭 또한 다양한 방법들이 제안되고 있다. 그 중 현재 그리고 가까운 장래에 촉망되는 방법으로 파장 라우팅 (Wavelength Routing: WR) 방식과 광 버스트 스위칭 (Optical Burst Switching: OBS) 방식이 활발히 연구되어지고 있다. 본 논문에서는 이러한 두 스위칭 방식을 적용시킨 파장 라우팅 네트워크와 광 버스트 스위칭 네트워크의 성능을 평가 비교해보고, 광 버스트 스위칭 네트워크가 파장 라우팅 네트워크에 비하여 우수한 성능을 보일 수 있는 조건들을 도출하였다. 또한, 이러한 결과들을 바탕으로 IP over WDM 네트워크에서 광 버스트 스위칭이 효율적으로 우수하다는 것을 입증하였다.

키보드와 마우스 사용시 착용식 손목 지지대 효과 (The Effect of Wearable Wrist Rest During Keyboard and Mouse Use)

  • 박경수;박강효;홍기범
    • 대한인간공학회지
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    • 제27권3호
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    • pp.33-41
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    • 2008
  • The goal of this study was to compare wrist posture, muscular loads and perceived comfort among wearable wrist rest (WR), general wrist rest(GR), no wrist rest(NR) during keyboard and mouse use. Thirteen subjects performed text editing task in three test conditions: wearable wrist rest(WR), general wrist rest(GR), no wrist rest(NR). During text editing task, the right wrist posture was recorded by an electrogoniometer and the muscle activity in upper trapezius, anterior deltoid, extensor digitorum, extensor carpi ulnaris were recorded by electromyography. After all of the tests, the subjects rated perceived comfort. Working with wearable wrist rest(WR), compared to no wrist rest(NR) and general wrist rest(GR), decreased wrist radial/ulnar deviation and also decreased muscle activity in upper trapezius and anterior deltoid. At the same time, in work with wearable wrist rest(WR), the subjects rated more comfort at 5 of 8 body locations(shoulder, upper arm, wrist, hand, body).

Ka-대역 직교모드변환기 설계 (Design of a Ka-Band Orthomode Transducer)

  • 이종경;채범용;박동희;안병철
    • 한국전자파학회논문지
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    • 제15권1호
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    • pp.110-118
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    • 2004
  • 본 논문에서는 21/31 GHz 대역 직교모드변환기의 설계 기법을 제시하였다. 공용포트에는 8.38${\times}$8.38 mm의 정사각형 도파관을 사용하였으며 직선포트에는 WR-34표준 사각형 도파관을 사용하였다. 직선포트는 다단 λ/4 임피던스변환기로 공용포트에 연결하였다. 측면포트는 공용도파관 중심선 상의 슬롯에 의해 공용포트와 결합되며 슬롯과 측면포트의 WR-51 표준 사각형 도파관 사이에 임피던스 정합구조를 사용하였다. 위와 같은 구조의 직교모드변환기를 도파관 이론에 기초한 반복설계에 의해 최적화하였다. 설계된 직교모드변환기를 제작, 측정하여 설계기법의 타당성을 확인하였다.

Triton WR-1339로 유발된 흰쥐의 고지혈증(高脂血症)에 대한 포황(蒲黃)의 실험적(實驗的) 연구(硏究) (Effects of Typha Angustata on Hyperlipidemia Rats Induced by Triton WR-1339)

  • 이선모;정찬길;김광호;소경순
    • 대한예방한의학회지
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    • 제8권1호
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    • pp.33-45
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    • 2004
  • In order to study the effects of Typha angustata on hyperlipidemia, we divided the rats into three groups(normal group, control group & sample group) and perfomed the experimental research. Hyperlipidemia rats were induced by Triton WR-1339 for 3days. The sample group was administerd the extract of Typha angustata 2ml/200g for 3 days and control group was administerd equal dose of saline. And then we measured the amount of serum Total cholesterol, Triglyceride, LDL-cholesterol, HDL-cholesterol, and Phospholipid. The results were as follows: 1. Typha angustata showed decreasing effects on Total cholesterol, Triglyceride, LDL-cholesterol, and Phospholipid levels in serum significantly(p<0.01) 2. Typha angustata showed and showed increasing effects on HDL-cholesterol level in serum significantly(p<0.05). According to the above results, Typha angustata showed significant decreasing effects on hyperlipidemia, and it is considered that it is appropriate to apply for hyperlipidemia.

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Modeling the mechanical properties of rubberized concrete using machine learning methods

  • Miladirad, Kaveh;Golafshani, Emadaldin Mohammadi;Safehian, Majid;Sarkar, Alireza
    • Computers and Concrete
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    • 제28권6호
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    • pp.567-583
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    • 2021
  • The use of waste materials as a binder or aggregate in the concrete mixture is a great step towards sustainability in the construction industry. Waste rubber (WR) can be used as coarse and fine aggregates in concrete and improves the crack resistance, impact resistance, and fatigue life of the produced concrete. However, the mechanical properties of rubberized concrete degrade significantly by replacing the natural aggregate with WR. To have accurate estimations of the mechanical properties of rubberized concrete, two machine learning methods consisting of artificial neural network (ANN) and neuro-fuzzy system (NFS) were served in this study. To do this, a comprehensive dataset was collected from reliable literature, and two scenarios were addressed for the selection of input variables. In the first scenario, the critical ratios of the rubberized concrete and the concrete age were considered as the input variables. In contrast, the mechanical properties of concrete without WR and the percentage of aggregate volume replaced by WR were assumed as the input variables in the second scenario. The results show that the first scenario models outperform the models proposed by the second scenario. Moreover, the developed ANN models are more reliable than the proposed NFS models in most cases.

Triton WR-1339 주사에 의한 고지혈증 유발시 간세포내 지방 축적에 관한 형태학적 연구 (Accumulation of Lipid Including Cholesterol in Murine Hepatocytes with Hyperlipidemia Induced by Triton WR-1339)

  • 박인식;안상현;김진택
    • 동국한의학연구소논문집
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    • 제6권1호
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    • pp.107-115
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    • 1997
  • 본 실험은 Triton WR-1339를 생쥐에 복강주사한 후 시간의 경과에 따른 간조직의 일반적인 형태변화와 간세포내의 콜레스테롤을 비롯한 지방입자의 분포변화를 관찰하기 위해 시행되었다. Triton 주사 후 간조직에서 나타난 일반적인 형태변화는 48시간에서 그물구조의 세포질룰 가진 간세포가 간엽 전체에서 관찰되었고, 간세포 손상으로 인해 간세포판은 사라졌다. 간조직내의 지방분포변화는 triton주사 후 48시간에 전체 간엽에서 지방입자의 과출현을 확인할 수 있었으며, 지방입자의 크기도 대조군에 비해 큰 것으로 나타났다. 간조직내의 콜레스테롤입자의 분포 변화는 triton 주사 후 48시간에 콜레스테롤입자가 간엽전체에서 과출현하는 것이 관찰되었다. 이상의 결과로 볼 때 triton 주사 후 지방대사이상에 의해 그 결과 간조직내에서 콜레스테롤를 비롯한 지방입자의 축적이 증가되는 고지혈증 병변이 유도된 것으로 사료된다.

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Effects of adlay, buckwheat, and barley on transit time and the antioxidative system in obesity induced rats

  • Kim, Jung-Yun;Son, Bo-Kyung;Lee, Sang-Sun
    • Nutrition Research and Practice
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    • 제6권3호
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    • pp.208-212
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    • 2012
  • In the present study, we examined whether four grains including adlay (AD), buckwheat (BW), glutinous barley (GB), and white rice (WR) affect the duration of food residence in the gastrointestinal tract and hepatic enzyme activities in rats fed different combinations of the grains. The rats were raised for 4 weeks on a high fat diet based on the American Institute of Nutrition-93 (AIN-93G) diets containing 1% cholesterol and 20% dietary lipids. Forty male rats were divided into four groups and raised for 4 weeks with a diet containing one of the grains. Corresponding to the dietary fiber contents of the experimental grains, gut transit time was shortest in the rats fed GB and increased in the order of BW, AD, and WR. In addition, the accumulated shortest transit time occurred in the GB group. Gut transit time affected weight gain and major organ weight, as it was closely related to the absorption of nutrients. The level of thiobarbituric acid reactive substance (TBARS) in liver was higher in rats fed WR, AD, BW, and GB, indicating that the other grains decreased oxidative stress in vivo more than WR. Glutathione, glutathione peroxidase, and glutathione S-transferase levels in the AD, BW, and GB groups were significantly higher than those in the WR group. In conclusion, reduced colonic transit time has been implicated in reducing the incidence of colon cancer, as evidenced by populations consuming diets rich in fiber. Whole grains such as AD, BW, and GB may contribute to a significant supply of antioxidants to prevent oxidative stress if they are consumed in large amounts.